Chemicals are commonly found in dog urine, which means the dogs are absorbing the chemicals.
A study at Tufts University School of Veterinary Medicine showed that lawn pesticides are related to malignant lymphoma found in dogs. From the study: “specifically, the use of professionally applied pesticides was associated with a significant 70% higher risk of CML. The risk was also higher in those reporting use of self-applied insect growth regulators.”
Another study showed that herbicides are also related to increased risk of malignant lymphoma in dogs.
And yet another study showed that chemicals on lawns increase the odds that a dog will develop bladder cancer.
This also elevates the potential risks or humans seeing that animal studies often translate to human results. Non-Hodgkin’s lymphoma has been linked to similar studies as well.